1. Polymer-based Thermoelectric Devices School of Chemical Engineering Purdue University Thursday August 7, 2014 Stuart W. A. Hilsmier, Edward P. Tomlinson, and Bryan W. Boudouris To Load T HOT T COLD

2. Need for Waste Energy Recovery Source: Lawrence Livermore National Laboratory (www.llnl.gov) 1.Introduction (1 of 4) 2.Methods (2) 3.Results (1) 4.Conclusion (1)

3. Fundamentals of Thermoelectric Materials Used to compare efficiency of materials Parameters Seebeck Coefficient (S ): Measures the amount of energy an electron carries across the material Electrical Conductivity ( σ): Measure of the ability for electrons to move through the material Thermal Conductivity (κ ): Measures how easily heat can move through the material Material Figure of Merit (zT) To Load T HOT T COLD 1.Introduction (2 of 4) 2.Methods (2) 3.Results (1) 4.Conclusion (1)

4. Uses of Thermoelectric Devices Reduce Weight Improve efficiency Reliable 1.Introduction (3 of 4) 2.Methods (2) 3.Results (1) 4.Conclusion (1)

5. Organic Molecules in Thermoelectric Device Poly(2,2,6,6-tetramethyl-1-piperidinyloxy-4-yl methacrylate)  PTMA Testing films doped with 4-ethylbenzenesulfonic acid  EBSA PTMA previously used in solid-state [3] Has well-documented conductivity [1-2] Question: What effects will doping PTMA with EBSA have on its conductivity, Seebeck coefficient, and thermoelectric power factor? 1.Introduction (4 of 4) 2.Methods (2) 3.Results (1) 4.Conclusion (1)

6. From Solution to Device Prepare solution Mass compounds Add solvent Stir until dissolved Heat to evaporate solvent Paint silver contacts on Apply solution to substrate 1.Introduction (4) 2.Methods (1 of 2) 3.Results (1) 4.Conclusion (1)

7. Conductivity and Seebeck Testing Current Voltage 40˚C Voltage ΔTΔT T Hot T Cold 1.Introduction (4) 2.Methods (2 of 2) 3.Results (1) 4.Conclusion (1)

8. Results 1.Introduction (4) 2.Methods (2) 3.Results (1 of 1) 4.Conclusion (1) Mass Percent EBSA vs Conductivity

9. Conclusions and Future Work 1.Introduction (4) 2.Methods (2) 3.Results (1) 4.Conclusion (1 of 1) Conductivity increases with larger mass percent of EBSA Seebeck data necessary to determine power factor of devices Percent EBSA vs Seebeck and Power Factor (Example Data)

10. References 1.Rostro, L.; Baradwaj, A. G.; Boudouris, B. W. ACS Appl. Mater. Interfaces 2013, 5, 9896–9901. 2.Rostro, L.; Wong, S. H.; Boudouris, B. W. Macromolecules 2014, 47, 3713–3719. 3.Yonekuta, Y.; Susuki, K.; Oyaizu, K.; Honda, K.; Nishide, H. J. Am. Chem. Soc. 2007, 129, 14128–14129.

11. Acknowledgements